图形验证码

这是java代码！
如若使用tomcat容器启动项目则需要加上这句代码，java的图片处理包需要图形环境，否则会报这个错server(X11 window server using ':0.0' )。而通过java -Djava.awt.headless=true 这个参数的指定就可以避免java 2d去找图形环境
System.setProperty("java.awt.headless", "true");
@RequestMapping("/getImage")
public String getImage(){
return "user/code";
}

@RequestMapping("/checkCode")
public void checkImage(HttpServletRequest request, HttpServletResponse response, Model model) throws Exception{
Map<String,Object> returnMap = new HashMap<String,Object>();
if(smsDubboService.isTest()){
returnMap.put("result", "1");
returnMap.put("msg", "成功");
SystemUtil.mapToJson(returnMap,response);
return;
}

String imgCode = (String) request.getParameter("imgCode");
String sessionCode = (String) super.getSession().getAttribute("code");

log.info("【图片验证码验证》输入值:】" + imgCode +",Session里存储的值:" + sessionCode);

if(StringUtils.isBlank(imgCode) || StringUtils.isBlank(sessionCode)){
returnMap.put("result", "0");
returnMap.put("msg", "验证码错误");
SystemUtil.mapToJson(returnMap,response);
return;
}

imgCode = imgCode.toLowerCase();

if(imgCode.equals(sessionCode.toLowerCase())){
returnMap.put("result", "1");
returnMap.put("msg", "成功");
SystemUtil.mapToJson(returnMap,response);
return;
}else{
returnMap.put("result", "0");
returnMap.put("msg", "验证码错误");
SystemUtil.mapToJson(returnMap,response);
return;
}

}
codejsp代码；
<%@ page contentType="image/jpeg" import="java.awt.*,java.util.*,java.awt.image.*,javax.imageio.*" pageEncoding="UTF-8" %>
<%!
Color getRandColor(int fc,int bc){//给定范围获得随机颜色
  Random random = new Random();
  if(fc>255) fc=255;
  if(bc>255) bc=255;
  int r=fc+random.nextInt(bc-fc);
  int g=fc+random.nextInt(bc-fc);
  int b=fc+random.nextInt(bc-fc);
  return new Color(r,g,b);
  }
%>
<%
//设置页面不缓存
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);

// 在内存中创建图象
int width=104, height=34;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

// 获取图形上下文
Graphics g = image.getGraphics();

//生成随机类
Random random = new Random();

// 设定背景色
g.setColor(new Color(241,244,245));
g.drawRect(0, 0, width, height);
g.setColor(new Color(241,244,245));
g.fillRect(0, 0, width, height);
//设定字体


// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到


// 取随机产生的认证码(4位数字)

g.setFont(new Font("微软雅黑",Font.BOLD,20));
String codeList = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";

StringBuffer sRand= new StringBuffer("");


for (int i=0;i<4;i++){
  int a=random.nextInt(codeList.length()-1);
  String rand=codeList.substring(a,a+1);
  sRand.append(rand);
  // 将认证码显示到图象中
  g.setColor(new Color(80,201,64));//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
  //g.translate(random.nextInt(3), random.nextInt(3));
  g.drawString(rand,23*i+6,26);
}

// 将认证码存入SESSION
session.removeAttribute("code");
session.setAttribute("code",sRand.toString());
// 图象生效
g.dispose();

// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());
out.clear();
out = pageContext.pushBody();


%>

js代码；
//点击获取新图片
function getImage(obj){
$(obj).attr("src","../verifyCode/getImage.do?" + Math.random());
}

//验证图片验证码吗
function checkCode(login_img_code){
var code_img = true;
$.ajax({
type: "post",
url: "../verifyCode/checkCode.do",
async : false,
data: {imgCode:login_img_code},
dataType: "text",
success: function(data){
var resultData = eval("(" + data + ")");
if(resultData.result == "0"){
code_img = false;
}else{
code_img = true;
}
},
error: function(){
}
});

return code_img;
}